Energy-efficient power control for macro-femto networks

Driven by dramatic increase in the number of users and data usage, the rapidly increasing energy consumption in mobile cellular networks has become an urgent concern to address recently. Macro-femto network has been considered as one of the most promising infrastructure for the upcoming next generation cellular networks, where the energy efficiency issue has not been well investigated as most existing related work is focused on spectrum sharing and interference avoidance. In this paper, we study transmit power control for macro-femto networks, aiming at maximizing energy efficiency while meeting the requirement of received signal-to-interference-plus-noise ratio (SINR). We design an energy-efficient power control (EEPC) scheme for closed access femtocell networks. In EEPC scheme, the macro base station (BS) and femto access points (FAPs) periodically exchange information on the gradient of allocated power and the total system power. The BS or a FAP adjusts the transmit power of allocated resource blocks (RBs) based on the information it receives. We conduct extensive simulation experiments to validate the effectiveness of EEPC scheme and numerical results show that EEPC can effectively improve the system energy efficiency while satisfying the minimum SINR requirements of the macrocell users and the femtocell users well.